In this chapter we will survey the field of 2D materials beyond graphene to summarize the present state of the art in experimentally and theoretically studied layer structures. Some of the general reasons behind the unusual energetic properties of 2D systems will be discussed, and the accuracy of different ab initio techniques will by surveyed. We will also touch on the future of heterostructured materials and highlight how computers and theory, and especially the theory of van der Waals and related forces, will play a role in producing new, useful materials.